The present invention relates to a device for protecting against liquids being splashed into a vapor-only-withdrawal conduit of an LP gas tank or the like used on a recreational vehicle or the like. The present invention also relates to a check valve.
Many recreational vehicles and the like have LP gas tanks mountable thereon for use in providing a power source for appliances. When the vehicle moves, the LP gas, which is under pressure in the tanks, is shaken around causing the liquid component of the LP gas to splash into the liquid withdrawal conduit of the tank. The problem that results is, when the liquid is dispensed out of the tanks along with the desired gas, appliances are caused to malfunction and regulators are damaged and frozen. Consequently, it is desirable that LP gas tanks be provided with means for preventing the liquid component of the LP gas from being dispensed along with the gas component thereof.
A check valve has in the past been designed in such a way so as to have a cavity or depression in the inlet end of the check valve as typified by the patent to Wynn, U.S. Pat. No. 4,129,145. Devices such as Wynn allow liquid to be trapped in the inlet cavity. When the valve is opened to allow a gas to pass, the liquid is passed along as well. Non-gaseous liquid in the vapor withdrawal conduit can cause regulator damage, regulator freeze-ups and appliance malfunction.
Some valves have also been designed as typified by the patent to Behle, U.S. Pat. No. 4,114,636 with an air inlet and outlet valve for a tank. Disclosed is an upper ball type valve which allows air to enter or leave the tank through the conduit when the ball is in an unseated position. Liquid in the tank causes the ball to move into a seated position blocking the entrance to the conduit.
Other possibly relevant references are: Kramer, U.S. Pat. Nos. 1,614,561; Scott, 2,301,821; Buttner et al., 2,405,998; St. Clair, 2,638,924; Davis, 3,335,751; Howard, 3,736,956; Fanshier, 3,794,077; Stover, 3,822,028; Behle, 4,114,636; Wynn, 4,129,145; Firestone, 4,131,129; Smith, 3,106,956; Ward, 1,947,366.